No one is going to argue with a male swinging around his proboscis on the beach. In that way, size has become the dominant gene in the evolutionary trajectory of the elephant seal.
But size is not costless for the elephant seal. It makes them easy prey on land. At times in the past, this has threatened their very existence. In the 18th century, their main land predator - man - hunted elephant seals for their blubber and fur. In the 19th century, their numbers fell rapidly to below 100 and for a time they were believed to be extinct. Just in time, governments intervened to place restrictions on hunting, nationally and internationally. Today, elephant seal numbers have swelled to above 800,000. The hand of government has protected them from man – and from themselves.
The pattern is found throughout the animal world, in features as conspicuous as over-sized antlers and over-elaborate plumage. In many cases, these physiological features have evolved as a response to a competitive sexual race, a Darwinian tournament. Matthew Ridley calls this the Red Queen Race from the Alice in Wonderland scene in which “however fast they went, they never seemed to pass anything. As elephant seals, deer and peacocks can attest, it is a race in which, in their quest to win, the species as a whole may end up as loser.